Muffler for two cycle diesel pile hammer

ABSTRACT

A muffler for a two cycle internal combustion cylinder having a common intake and exhaust port is disclosed. The muffler finds preferred use on a two cycle diesel pile hammer having a common intake and exhaust port. The muffler includes a short pipe communicating to and from the port. The short pipe is communicated concentrically to a larger perforated cylindrical sleeve open at the top and at the bottom. This larger perforated cylindrical sleeve has a lower heavily perforated portion, an upper less perforated portion, and a pipe extending substantially transverse of the sleeve between the upper and lower portions. During intake of the air to be combusted interior of the pile hammer diesel cylinder, air is drawn mainly through the lower heavily perforated portion of the sleeve to provide an air intake to the hammer substantially uncontaminated by exhaust. During discharge of the combusted air from the interior of the pile hammer, the blast of discharged air -typically at speeds approaching sonic velocity- bypasses the lower sleeve portion. This air impacts the pipe extending transverse of the perforated sleeve and thereafter is muffled in sound as it passes through the remainder of the sleeve and the sleeve&#39;&#39;s perforation. Reduction in sound by as much as 10 decibels can occur without appreciable loss in pile hammer impact efficiency.

United States Patent 1 1 Heacox 1 1 MUFFLER FOR TWO CYCLE DIESEL PlLEHAMMER [75] Inventor: Russel L. Heacox, Tiburon Calif.

[73] Assignee: P & Z Company. Inc., South San Francisco. Calif.

22 Filed; June 26, 1974 121 App]. No.: 483,205

[52] US. Cl 181/36 R; 181/36 D; 181/49. 123/65 SP; 173/46; 173/D1G. 2[51] Int. Cl. FOlN 3/06 [58] Field of Search... 181/35 A, 36 11,36 A. 36D 181/40, 41. 49, 55. 56, 61], 72; 611/314;

123/65 R. 65 SP. 46 H 139 H. 79 R; 173/46 134, )(1. DIG. 2

Primary E.i'amiIzerStephen J. Tomsky Assistant Examiner-lohn F. GonzalesAttorney, Agent or Firm-Townsend and Townsend Lil [ 71 ABSTRACT Amuffler for a two cycle internal combustion cylinder having a commonintake and exhaust port is disclosed. The muffler finds preferred use ona two cycle diesel pile hammer having a common intake and exhaust port.The muffler includes a short pipe communicating to and from the port.The short pipe is communicated concentrically to a larger perforatedcylindrical sleeve open at the top and at the bottom. This largerperforated cylindrical sleeve has a lower heavily perforated portion, anupper less perforated portion, and a pipe extending substantiallytransverse of the sleeve between the upper and lower portions Duringintake of the air to he combusted interior of the pile hammer dieselcylinder, air is drawn mainly through the lower heavily perforatedportion of the sleeve to provide an air intake to the hammersubstantially uncontaminated by exhaust. During discharge of thecombusted air from the interior of the pile hammer. the blast ofdischarged air typically at speeds approaching sonic velocity bypassesthe lower sleeve portion. This air impacts the pipe extending transverseof the perfo rated sleeve and thereafter is muffled in sound as itpasses through the remainder of the sleeve and the sleeves perforation.Reduction in sound by as much as 11) decibels can occur withoutappreciable loss in pile hammer impact efficiency.

9 Claims 5 Drawing Figures MUFFLER FOR TWO CYCLE DIESEI, PILE HAMMERThis invention relates to mufflers and. more particu larly. to atnufller for a two cycle cylinder having a common intake and exhaustport. Specifically. the mul ller is adapted to the intake exhaust portof a diesel pile hammer.

SUMMARY OF 'l'Hl'f PRIOR ART To the extent that noise produced by theexhaust from internal combustion cylinders is understood. the soundapparently emanates from the exhaust port when it opens. Specifically,the instant the exhaust port opens. gases interior of the cylinder areexhausted with great energy and force. 'l'hese gases are pushed past theport at velocities approaching sonic velocities. Moreover. the energywith which the exhaust gases are pushed by the opening port exceeds thatenergy re quired to drive the gases at the speed of sound. Loud noiseapparently results.

Diesel pile hammers and their internal combustion cylinder exhausts areparticularly obnoxious. The sound and vibration of the hammer impactcombines with the sound and vibration of the noise generated by thediesel exhaust. llie two sounds combined in sulv stantially the sameinstant of time result in an intolerable loud. obnoxious noise. Morerecently. this type of noise has been referred to as acousticalpollution."

Mufflers heretofore known have been used on either air intakes or airexhausts. but not both. Where niachincry utilizes the same port for bothintake and ex haust. a peculiar problem arises. Providing a muffler withan elongate. circuitous muflling path not only generates undesirableback pressure resulting in ma chine inefficiencybut additionally resultsin exhaust air being rechanneled into the machinery upon cylinder strokeintake. Pile hammer efficiency drops and even damage to the hammer canresult. Conventional oneway mufflers. either of the exhaust or intakevariety. are of little use in muffling two cycle internal combustionequipment having a common intake and exhaust port.

SUMMARY OF THE INVENTION A muffler for a two cycle internal combustioncylin der having a common intake and exhaust port is dis closed. Themuffler finds preferred use on a two cycle diesel pile hammer having acommon intake and exhaust port. The muffler includes a short pipecommunicating to and from the port. The short pipe is communicatedconcentrically to a larger perforated cylindrical sleeve open at the topand at the bottom. This larger perforated cylindrical sleeve has a lowerheavily perforated portion. an upper less perforated portion. and a pipeextending substantially transverse of the sleeve be tween the upper andthe lower portions. During intake of the air to be combusted interior ofthe pile hammer diesel cylinder. air is drawn mainly through the lowerheavily perforated portion of the sleeve to provide an air intake to thehammer substantially Ul'ttD ntaminated by exhaust. During dischargeofthc combusted air from the interior of the pile hammer. the blast ofdischarged air -typically of speeds approaching sonic velocitybypassesthe lower sleeve portion. This air impacts the pipe extending transverseof the perforated sleeve and thereafter is muffled in sound as it passesthrough the remainder of the sleeve and the sleeves perforation.Reduction in sound by as much as l() decibels can occur withoutappreciable loss in pile hammer impact efficiency.

OBJECTS. FliA'lURES AND ADVAN'IAGIIS OF THE lNVliN'llON An object ofthis invention is to disclose a muffler for the common intake-exhaustport on a two cycle internal combustion cylinder. According to thisaspect of the invention. the port is discharged concentrically into acylinder having lower and upper perforated sleeves. 'fhese sleeves aredivided by a transverse pipe. Preferably. the lower perforations aremore numerous than the upper perforations.

An advantage of the muffler is that intake occurs largely through thelower. more perforated sleeve portion. Small amounts of exhaust gas aretherefore cn trained during the intake stroke. The result is that noappreciable loss occurs in cylinder efficiency.

Another advantage of this invention is that the exhaust largely bypassesthe lower. grossly perforated portion of the sleeve. Specifically. itpasses upwardly and is deflected at a transverse pipe extending over theexhaust port. 'l'hereafter. the deflected gas impinges on the sleevesides. typically at the upper. less perforated portion of the sleeve.Muffling of approximately ll) percent of the acoustical vibrationoccurs. Reductions from 99 dba have been made to 88 dba using suchapparatus on a diesel pile hammer internal combustion cylinder.

An object of this invention is to disclose a muffler which can be usedon a two cycle pile hammer. preferably a diesel pile hammer.

A further advantage of this invention is to decouple the sound oftheexhaust port opening from the physical impact of a pile hammer with apile. This decoupling results in an acoustically much more tolerablesound which is appreciably less disruptive ofthc environment. Bothoperating crews and persons inevitably present in the operatingenvironment are much less offended by pile hammer noise pollution.

A further object of this invention is to disclose a mufller that canhold together in the vibrating ambient of a pile hammer. According tothis aspect of the invention. the perforated sleeve is constructed of aheavy steel. This steel sleeve is bolted directly to the pile hammer andmoves in vibration with the pile hammer.

An advantage of the disclosed muffler is that the muffler can holdtogether for virtually the same period of time as the pile hammeritself.

A further advantage of the muffler is that the use of flexibleconnections between a muffler and the vibrat ing hammer is not required.Instead. the muffler assembly is capable of integral attachment to thepile hammer itself.

Other objects. features and advantages of this invention will becomemore apparent after referring to the following specification andattached drawing in which:

FIG. 1 is a front elevation in perspective illustrating a diesel pilehammer mounted to conventional pile leads, with the exhaust muffler ofthis invention attached thereto;

FIG. 2 is a view of a portion of the pile hammer illustrating a conduitattached leading to the muffler;

FIG. 3 is a side elevation of the completed muffler attached to theexhaust conduit;

FIG. 4 is a side elevation of the large perforated sleeve of theinvention; and,

FIG. 5 is a section of the pile hammer taken along lines S5 of FIG. 4.

Referring to FIG. 1, a pile hammer A is illustrated mounted toconventional pile leads 8 driving at a hammer C a pile D. Intake-exhaustports 14 are illustrated having a pipe segment 16 with the muffler E ofthis invention attached thereto.

The pile hammer here illustrated is a Kobe Model KB-42 diesel pilehammer, a product of Kobe Steel Limited of Kobe, Japan. In the FIG. Ihere shown, two mufflers are illustrated. In the actual pile hammer, twomufflers appear on the front or illustrated side of the hammer.Similarly, and in complementary positions in the rear, two mufflers areinstalled to similar exhaust ports 14 at the rear of the pile hammer.These rear pile exhaust ports 14 are not shown.

Referring to FIG. 2, a four-inch tube 16 is welded to the exhaust portof the pile hammer. Preferably, the tube has a minimum length so as tocommunicate the intake and exhaust to the concentrically mounted,larger, outer perforated sleeve 40. On a pile hammer of the Kobemanufacture, the four-inch pipe 16 of 12 inches in length has been foundsatisfactory.

It is typically preferable to angle the discharge port away from thepile hammer. To this end, an angle of approximately 8 is placed in thefour-inch pipe leading away from the exhaustintake port 14 of the pilehammer.

Referring to FIG. 2, paired bolts 28, are welded to diametricallyopposite portions of pipe segment 16. These bolts are approximately 6inches in length and have threaded thereto at their upper portion nuts31, 32. As will hereinafter more fully appear, the sleeve constitutingthe muffler of this invention is mounted on top of nuts 3], 32.Thereafter, nuts 61, 62 complementary to nuts 31, 32 are threaded overthe ends of the bolts 28, 30 to securely capture the muffler therebetween.

The simplified construction of the muffler of this invention can readilybe understood with reference to FIGS. 3, 4 and 5. Referring to FIG. 4,it will be seen that a cylinder 40 is provided. As specifically appliedto the Kobe hammer, cylinder 40 is approximately 14 inches in length, 6inches in diameter, and constructed of 3/16 inch wall tubing. The areaof the outside sleeve 40 exceeds the area of the concentricallycommunicating pipe by a ratio of approximately 50 percent. I

A pipe 42 extends transverse of the sleeve sidewalls. As here shown, itextends between the sidewalls of the cylindrical sleeve and provides acylindrical surface over which the exhaust gases pass. Pipe 42 hereshown is a one-inch diameter pipe.

The perforated portions of the sidewalls 40 of the cylinder above andbelow the pipe can be very briefly discussed. Above the pipe, theperforated portions 44 of the cylinders constitute an interruption ofapproximately 20 to 40 percent of the sleeve 40 sidewalls. Below thepipe 42, the perforations 46 in the sides of the pipe interrupt between40 and 60 percent of the sidewall area. The perforations below areevenly disbursed and many are elongate in nature axially of thecylindrical length of the cylinder. As will hereinafter be explained,the apertures 46 are those apertures through which the greater portionsof the intake occurs.

Mounting of the sleeve can easily be understood. Specifically, andmedially of the perforated sleeve, two ears 50, 52 are cut andthereafter bent horizontally from the sleeve 40 sidewalls (see FIGS. 4and 5). These ears are bent horizontally and transpierced by apertures54.

In installation of the sleeve, the apertures are passed over the upperportions of bolts 28, 30. Thereafter, bolts 61, 62 rigidly secure theperforated sleeve to the exhaust pipe 16. It should be noted that bothends of sleeve 40 are open. Moreover, sleeve 40 overlaps pipe 16 by 4inches of the embodiment here shown or more than one half a diameter ofthe sleeve.

Operation can readily be understood. During intake, the bulk of theintake gases pass inwardly through the conduit 16 to the pile hammerport 14 through apertures 46. Upon exhaust discharge from the hammer,gases at high velocity impinge upon pipe 42 mounted transversely of theperforated cylinder 40. Muffling of the sound by passage around the pipeand impingement on the upper perforation of the sleeve occurs. Sound iscorrespondingly reduced.

It should be apparent that the embodiment here shown will admit ofmodifications. For instance, the in vention can be utilized withvirtually any type of two cycle engine device having a common intake andexhaust port. Moreover, its use to a particular type of pile hammer isnot required. It can be used with virtually any type of diesel pilehammer. Further, it will be realized by those skilled in the engine artthat two cycle gas as well as two cycle diesel internal combustiondevices having common intake and exhaust ports can utilize the inventionherein disclosed. Likewise, other modifications can be made to thisinvention.

I claim:

1. A muffler for a two cycle internal combustion engine having a commonintake and exhaust port comprising: a perforated cylindrical sleeve; aconduit communicating from said common intake and exhaust port to one ofthe open ends of said sleeve; means for mounting said sleeve and conduitto said common port; and, an obstructing member mounted transverse ofsaid perforated sleeve over the outlet of said conduit.

2. The invention of claim 1 and wherein said conduit extends interiorlyof said sleeve by a distance equal to one half the diameter of saidsleeve.

3. The invention of claim 1 and wherein said obstructing membercomprises a cylindrical surface mounted transverse of said sleeve.

4. The invention of claim I and wherein the cross sectional area of saidsleeve exceeds the cross sectional area of said conduit by 50 percent.

5. In combination, a pile hammer having at least one two cycle internalcombustion cylinder with a common intake and exhaust port; a perforatedcylindrical sleeve; a conduit communicating from said common intake andexhaust port to one of the open ends of said perforated sleeve; meansfor mounting said sleeve and conduit to said pile hammer; and, anobstructing member mounted transverse of said perforated sleeve over theoutlet of said conduit.

6. The combination of claim 5 and wherein said mounting means includessaid conduit rigidly welded to said pile hammer, and said sleeve rigidlyattached to said conduit only.

sleeve and the perforations below said obstructing transverse member,and towards said conduit interrupt 20 to 40 percent of the area of saidsleeve sidewalls.

9. The invention of claim 5 and wherein said pile hammer is a dieselpile hammer.

1. A muffler for a two cycle internal combustion engine having a commonintake and exhaust port comprising: a perforated cylindrical sleeve; aconduit communicating from said common intake and exhaust port to one ofthe open ends of said sleeve; means for mounting said sleeve and conduitto said common port; and, an obstructing member mounted transverse ofsaid perforated sleeve over the outlet of said conduit.
 2. The inventionof claim 1 and wherein said conduit extends interiorly of said sleeve bya distance equal to one half the diameter of said sleeve.
 3. Theinvention of claim 1 and wherein said obstructing member comprises acylindrical surface mounted transverse of said sleeve.
 4. The inventionof claim 1 and wherein the cross sectional area of said sleeve exceedsthe cross sectional area of said conduit by 50 percent.
 5. Incombination, a pile hammer having at least one two cycle internalcombustion cylinder with a common intake and exhaust port; a perforatedcylindrical sleeve; a conduit communicating from said common intake andexhaust port to one of the open ends of said perforated sleeve; meansfor mounting said sleeve and conduit to said pile hammer; and, anobstructing member mounted transverse of said perforated sleeve over theoutlet of said conduit.
 6. The combination of claim 5 and wherein saidmounting means includes said conduit rigidly welded to said pile hammer,and said sleeve rigidly attached to said conduit only.
 7. The inventionof claim 5 and wherein the perforations of said sleeve interrupt atleast 20 percent of the sidewall area of said cylindrical sleeve.
 8. Theinvention of claim 5 and wherein the interruption of said sleeve abovesaid obstructing member interrupts 40 to 60 percent of the sidewall areaof said sleeve and the perforations below said obstructing transversemember, and towards said conduit interrupt 20 to 40 percent of the areaof said sleeve sidewalls.
 9. The invention of claim 5 and wherein saidpile hammer is a diesel pile hammer.